LAGOS Analysis

Loading in data

First download and then specifically grab the locus (or site lat longs)

# #Lagos download script
LAGOSNE::lagosne_get(dest_folder = LAGOSNE:::lagos_path())
## Warning in LAGOSNE::lagosne_get(dest_folder = LAGOSNE:::lagos_path()): LAGOSNE data for this version already exists on the local machine.
##   Re-download if neccessary using the 'overwrite` argument.'
#Load in lagos
lagos <- lagosne_load()
## Warning in (function (version = NULL, fpath = NA) : LAGOSNE version unspecified,
## loading version: 1.087.3
#Grab the lake centroid info
lake_centers <- lagos$locus

Convert to spatial data

#Look at the column names
#names(lake_centers)

#Look at the structure
#str(lake_centers)

#View the full dataset
#View(lake_centers %>% slice(1:100))

spatial_lakes <- st_as_sf(lake_centers,coords=c('nhd_long','nhd_lat'),
                          crs=4326) %>%
  st_transform(2163)

#Subset for plotting
subset_spatial <- spatial_lakes %>%
  slice(1:100) 

subset_baser <- spatial_lakes[1:100,]

#Dynamic mapviewer
mapview(subset_spatial)

Subset to only Minnesota

states <- us_states()

#Plot all the states to check if they loaded
#mapview(states)
minnesota <- states %>%
  filter(name == 'Minnesota') %>%
  st_transform(2163)

#Subset lakes based on spatial position
minnesota_lakes <- spatial_lakes[minnesota,]

#Plotting the first 1000 lakes
minnesota_lakes %>%
  arrange(-lake_area_ha) %>%
    slice(1:1000) %>%
  mapview(.,zcol = 'lake_area_ha')

In-Class work

1) Show a map outline of Iowa and Illinois (similar to Minnesota map upstream)

#creating Iowa map
iowa <- states %>%
  filter(name == 'Iowa')%>%
  st_transform(2163)

#creating Illinois map
illinois <- states %>%
  filter(name == 'Illinois')%>%
  st_transform(2163)

#combining Iowa and Illinois
il_ia <- rbind(iowa, illinois)

#mapping Iowa and Illinois
mapview(il_ia)

mapview code chunk is from https://r-spatial.github.io/mapview/articles/articles/mapview_02-advanced.html

2) Subset LAGOS data to these sites, how many sites are in Illinois and Iowa

combined? How does this compare to Minnesota?

#Subset iowa and illinois lakes based on spatial position 
il_ia_lakes <- spatial_lakes[il_ia,]

Combined, there are 16,466 lakes in Illinois and Iowa. Minnesota alone, has 29,038 lakes. This means that Minnesota has 12,572 more lakes than Illinois and Iowa.

3) What is the distribution of lake size in Iowa vs. Minnesota?

  • Here I want to see a histogram plot with lake size on x-axis and frequency on y axis (check out geom_histogram)
#making iowa lakes 
iowa_lakes <- spatial_lakes[iowa,]

#combining iowa and minnesota
iamn <- rbind(iowa, minnesota) 

#subsetting spatial lakes for Minnesota and Iowa
ia_mn_lakes <- spatial_lakes %>%
  .[iamn,] %>%
  st_join(iamn)

#graphing minnesota and iowa together on ggplot
ggplot()+
         geom_histogram(filter(ia_mn_lakes,name == "Minnesota"), mapping = aes(lake_area_ha), bins = 30,color="darkblue", fill="lightblue")+
         scale_x_log10() +
  labs(title = "Minnesota Lake Size", x = "Lake Area (ha)", y = "Frequency") +
  geom_histogram(filter(ia_mn_lakes,name == "Iowa"), mapping = aes(lake_area_ha), bins = 30, color = "purple", fill = "pink") +
  scale_x_log10()+
  labs(title = 'Iowa vs Minnesota Lake Size', x = "Lake Area (ha)", y = 'Frequency')+
  facet_wrap(~name, nrow = 2)
## Scale for 'x' is already present. Adding another scale for 'x', which will
## replace the existing scale.

https://stackoverflow.com/questions/47596357/overlaying-two-ggplot-facet-wrap-histograms helped me write some of the histogram code chunk (for visualizations)

4) Make an interactive plot of lakes in Iowa and Illinois and color them

by lake area in hectares

#plotting iowa and illinois together
il_ia_lakes %>%
  arrange(-lake_area_ha) %>%
    slice(1:1000) %>%
  mapview(.,zcol = 'lake_area_ha')

5) What other data sources might we use to understand how reservoirs and

natural lakes vary in size in these three states?

Using data sets to quantify and gain a better understanding of lakes and reservoirs are very beneficial when looking at hydrological patterns, especially since climate change is looming over our heads. A journal from Michael Meyer, et. al, discusses how they combined different global datasets to create the most harmonic dataset that contains lake surface area, and water quantity and quality, and aquifer recharge at local, regional, and global scales. They combined, Global Water Bodies Data Base, LANDSAT data, and GRACE data to create this data set. This article shows how important it is to collect different types of data in order to create and discover the workings of our hydro-world. This large data set could help us understand the reservoirs and natural lakes in these states by showing us the recharge rates of the reservoirs.